Disadvantages to Problem-Based Learning

According to Wood (2003), the major disadvantage to this process involves the utilization of resources and tutor facilitation. It requires more staff to take an active role in facilitation and group-led discussion and some educators find PBL facilitation difficult and frustrating. It is resource-intensive because it requires more physical space and more accessible computer resources to accommodate simultaneous smaller group-learning. Students also report uncertainty with information overload and are unable to determine how much study is required and the relevance of information available. Students may not have access to teachers who serve as the inspirational role models that traditional curriculum offers.

Although students generally like and gain greater ability to solve real-life problems in problem-based learning courses, instructors of the methodology must often invest more time to assess student learning and prepare course materials, as compared to LBL instructors. Part of this frustration also stems from the amount of time dedicated to presenting new research and individual student findings regarding each specific topic, as well as the disorganised nature of brain-storming

Traditional assumptions of the students
The problem of the problem-based learning is the traditional assumptions of the students. Most of the students might have spent their previous years of education assuming their teacher as the main disseminator of knowledge. Because of this understanding towards the subject matter students may lack the ability to simply wonder about something in the initial years of problem-based learning.

Role of the instructor
The instructors have to change their traditional teaching methodologies in order to incorporate problem-based learning. Their task is to question students' knowledge, beliefs, give only hints to correct their mistakes and guide the students in their research. All these features of problem-based learning may be foreign to some instructors; hence they find it difficult to alter their past habits.

Pupil's evaluation
The instructors have to adapt new assessment methods to evaluate the pupils' achievement. They have to incorporate written examinations with modified essay questions, practical examinations, peer and self assessments etc. Problem-based has also been considered more favourable to female participants, whilst having equivocal impacts on their male counterparts when compared to lecture based learning.

Cognitive load
Sweller and others published a series of studies over the past twenty years that is relevant to problem-based learning, concerning cognitive load and what they describe as the guidance-fading effect. Sweller et al. conducted several classroom-based studies with students studying algebra problems. These studies have shown that active problem solving early in the learning process is a less effective instructional strategy than studying worked examples (Sweller and Cooper, 1985; Cooper and Sweller, 1987). Certainly active problem solving is useful as learners become more competent, and better able to deal with their working memory limitations. But early in the learning process, learners may find it difficult to process a large amount of information in a short time. Thus the rigors of active problem solving may become an issue for novices. Once learners gain expertise the scaffolding inherent in problem-based learning helps learners avoid these issues. These studies were conducted largely based on individual problem solving of well-defined problems.

Sweller (1988) proposed cognitive load theory to explain how novices react to problem solving during the early stages of learning. Sweller, et al. suggests a worked example early, and then a gradual introduction of problems to be solved. They propose other forms of learning early in the learning process (worked example, goal free problems, etc.); to later be replaced by completions problems, with the eventual goal of solving problems on their own. This problem-based learning becomes very useful later in the learning process.

Many forms of scaffolding have been implemented in problem-based learning to reduce the cognitive load of learners. These are most useful to enable decreasing ("fading") the amount of guidance during problem solving. A gradual fading of guidance helps learners to slowly transit from studying examples to solving problems. In this case backwards fading was found to be quite effective and assisting in decreasing the cognitive load on learners.

Evaluation of the effects of PBL learning in comparison to traditional instructional learning have proved to be a challenge. Various factors can influence the implementation of PBL: extent of PBL incorporation into curriculum, group dynamics, nature of problems used, facilitator influence on group, and the motivation of the learners. There are also various outcomes of PBL that can be measured including knowledge acquisition and clinical competence. Additional studies are needed to investigate all the variables and technological scaffolds, that may impact the efficacy of PBL.

Demands of implementing
Implementing PBL in schools and Universities is a demanding process that requires resources, a lot of planning and organization. Azer discusses the 12 steps for implementing the "pure PBL"

Prepare faculty for change
Establish a new curriculum committee and working group
Designing the new PBL curriculum and defining educational outcomes
Seeking Advice from Experts in PBL
Planning, Organizing and Managing
Training PBL facilitators and defining the objectives of a facilitator
Introducing Students to the PBL Program
Using 3-learning to support the delivery of the PBL program
Changing the assessment to suit the PBL curriculum
Encouraging feedback from students and teaching staff
Managing learning resources and facilities that support self-directed learning
Continuing evaluation and making changes (pg. 809-812)